/**
 * #      1513
 * 名称   仅含 1 的子串数
 * 链接   https://leetcode-cn.com/problems/number-of-substrings-with-only-1s
 * 题解   [135](https://leetcode-cn.com/problems/number-of-substrings-with-only-1s/solution)
 * 通过率 37.2%
 * 难道   中等
 */

